File with custom extension gets removed by Unity editor from Visual Studio project

Let's say i have an xml file in my VS project. It is accessible from VS project explorer and it's also present in the assets view in Unity editor. Then in VS i change its extension to something else and switch to Unity editor. Once i switch back to VS i see that this file is no longer present in the project explorer. Is this how it is intended to work? If yes, is there a way to tell Unity to keep this file in VS project?

 

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